Australian officials have said they are confident missing flight MH370 was flying on autopilot when it disappeared.

The Malaysia Airlines plane vanished on March 8, with 239 people onboard, while travelling from Kuala Lumpur to Beijing.

The search area in the hunt for the missing jet has shifted several hundred miles south from the intensely examined site in a remote stretch of Indian Ocean, where a remote underwater drone had been scouring 330 square miles of seabed.

Australian Deputy Prime Minister Warren Truss said the new search area, about 1,100 miles off Australia's west coast, is based on fresh analysis of existing satellite data.

He said: "The new priority area is still focused on the seventh arc, where the aircraft last communicated with satellite.

"We are now shifting our attention to an area further south along the arc based on these calculations."

Image Caption:A huge search of an area in the Indian Ocean has failed to find the plane

Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, said: "Certainly for its path across the Indian Ocean, we are confident that the aircraft was operating on autopilot until it ran out of fuel."

However, why the autopilot would have been set on a flight path so far off course, and when exactly it was switched on remains unknown.

The new search zone of up to 24,000 square miles (60,000 sq km) is in the southern corridor and is based on where the aircraft last communicated with an Inmarsat satellite.

A survey will be carried out by two surface vessels to map the ocean floor of the area, which will take three months.

A comprehensive underwater search, using powerful side-scan sonar capable of probing depths of more than four miles, will start in August and take up to 12 months to complete.

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Mr Truss said he was optimistic the latest search zone is the most likely crash site, but warned finding the plane remains a huge task.

He said: "The search will still be painstaking. Of course, we could be fortunate and find it in the first hour or the first day - but it could take another 12 months."

The switch in the hunt comes after it emerged acoustic pings thought to have come from the plane's two flight recorders were not from the aircraft after all, leaving search teams scouring the wrong area.

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It is thought the sounds came from a search boat or the ping detector itself, ruling out the area originally thought to be where the plane had come down.